Thanks Craig. Used the Spark with both LB 8 &16mm macro adapters (extension tubes). Borrowed a Canon (T3) to shoot the Spark. Normally shoot Pentax and Olympus. The Spark seems to have less field curvature than Composer/double glass at 5.6. Perhaps a more subtle look? May be imagining this since I am not used to this camera or the new extension rings. If different, will buy one to add optic to my composer.
thanks again
barondla